1. Technical Field
The present invention relates to a tape cartridge including a case and a single reel which is contained in the case and around which a recording tape such as a magnetic tape used as a record reproducing medium for a computer, is wound.
2. Description of the Related Art
A magnetic tape cartridge is known that includes a single reel which is contained in a case and around which a magnetic tape used as a data record reproducing medium for a computer is wound. A leader member, such as a leader block, leader pin or leader tape, is fixed to a leading end of the magnetic tape. The leader member is drawn from the magnetic tape cartridge by a drawing device provided in a drive system. The magnetic tape fastened to the leader member is wound around a take-up reel of the drive system.
In addition, a reel gear is inscribed in an annular shape at a center of a lower surface of the reel, which is exposed through the hole formed at a lower surface of the magnetic tape cartridge. A driving gear provided on a rotating shaft of the drive system is engaged with the reel gear to rotate the reel. Data is recorded onto the magnetic tape and the recorded data is reproduced by synchronously rotating the reel of the magnetic tape cartridge and the take-up reel of the drive system.
A large amount of information can be recorded in such a magnetic tape cartridge, and little space is required for accommodating the magnetic tape cartridge at the time of storage. The position of the opening and the type of the door for opening and closing the opening differ for each type of leader member. For example, when a leader pin 60 is provided at an end of a magnetic tape T wound around a reel 74, as shown in FIG. 11, an opening 68 for pulling-out of the leader pin 60 is formed in a side wall 64 of a case 62. The opening 68 is opened and closed by a door 66 which slides in the direction opposite to the direction (the direction of arrow P) of loading the magnetic tape cartridge into a drive device.
Further, a pair of upper and lower pin holding portions 70, which hold the leader pin 60 when the magnetic tape cartridge is not being used, are provided at the inner side of the opening 68 of the case 62. The pin holding portions 70 are concave portions which are substantially semicircular as seen in plan view, and portions thereof are open so that the leader pin 60 can enter therein and exit therefrom. The both end portions of the leader pin 60, which is in a state of standing upright, are inserted into these concave portions (pin holding portions 70). An anchor spring 72 is disposed in a vicinity of the pin holding portions 70. Due to the anchor spring 72 pushing the upper and lower ends of the leader pin 60 toward the inner sides of the respective pin holding portions 70, the leader pin 60 does not fall out from the pin holding portions 70.
When the leader pin 60 enters into and exits from the pin holding portions 70, the anchor spring 72 elastically deforms appropriately, so that movement of the leader pin 60 is permitted. Conventionally, the adjustment of the pushing force (elastic force) of the anchor spring 72 with respect to the leader pin 60 was carried out by adjusting the elastic force of the anchor spring 72 itself. Namely, the elastic force depended on the thickness the length, and the angle of bending of the anchor spring 72.
If the adjustment of the pushing force (elastic force) of the anchor spring with respect to the leader pin can only be carried out by adjusting the elastic force of the anchor spring itself in this way, spring fatigue occurs at the anchor spring due to repeated use. Thus, there are cases in which the force by which the anchor spring pushes the leader pin varies. There is the concern that the problem that the leader pin cannot be held stably will arise.